package com.lyz.dataStructure.LeetCode.stack;

import java.util.Stack;

/**
 *@Author:759057893@qq.com Lyz
 *@Date: 2019/5/7 20:42
 *@Description:
 **/
/*
设计一个支持 push，pop，top 操作，并能在常数时间内检索到最小元素的栈。

push(x) -- 将元素 x 推入栈中。
pop() -- 删除栈顶的元素。
top() -- 获取栈顶元素。
getMin() -- 检索栈中的最小元素。
示例:

MinStack minStack = new MinStack();
minStack.push(-2);
minStack.push(0);
minStack.push(-3);
minStack.getMin();   --> 返回 -3.
minStack.pop();
minStack.top();      --> 返回 0.
minStack.getMin();   --> 返回 -2.
 */

class MinStack {
    Stack<Integer>stack;
    Stack<Integer>minstack;
    /** initialize your data structure here. */
    public MinStack() {
        stack   =new Stack<Integer>();
        minstack=new Stack<Integer>();
    }

    public void push(int x) {
        if(minstack.isEmpty()||x<minstack.peek())
            minstack.push(x);
        else
            minstack.push(minstack.peek());
        stack.push(x);
    }

    public void pop() {
        minstack.pop();
        stack.pop();
    }

    public int top() {
        return stack.peek();
    }

    public int getMin() {
        return minstack.peek();
    }

    public static void main(String[] args) {
        MinStack stack = new MinStack();
        stack.push(5);
        stack.push(2);
        stack.push(-8);
        stack.push(1);
        stack.push(-2);
        System.out.println(stack.getMin());

    }
}
